As communication technology has been recently developed, many communication services using a wired or wireless manner have been provided to users. In wired communication systems, optical communication networks can be implemented by the development of a system related to the development of optical fiber and transmission speed and amount of voice and data have been increased. In addition, in wireless communication systems, voice and data services can be simultaneously provided to users during moving at a high speed. Furthermore, in wireless communication services, owing to mobile phone services using technology such as code division multiple access (CDMA), frequency division multiple access (FDMA), and time division multiple access (TDMA) and owing to wireless Internet services using technology such as wireless LAN, CDMA, and wireless broadband Internet (WBI), the number of service provision areas and the number of users have been rapidly increased.
Due to the development of wireless communication technology and an increase in the number of users of corresponding wireless communication services, service providers and users should consider the reliability and effectiveness of a method of imposing fees and providing services.
In this regard, communication service providers suggest various discount benefits and corresponding methods of imposing service fees so as to keep own customers and to attract new customers. The suggestions include mobile phone service providers' local discount services and DU phone services in which a mobile phone and a wired phone network are connected to each other.
Local discount services use cell-based technology in which discount benefits are provided to communication fees within a region in which a specific base station provides services. Here, cell-based technology is applied to a system having a base station, such as a mobile phone system and wireless Internet etc.
FIG. 1 illustrates a cell and a zone of a conventional mobile phone system. Referring to FIG. 1, the conventional mobile phone system includes a base station 6 which performs voice and data communication in a direct connection with a subscriber's mobile phone. The base station 6 constitutes a cell 2 which is a service provision area ranging from several hundreds of meters to several kilometers. In addition, for the reasons of subscribers and base station management etc., a zone 4 in which a plurality of cells, that is, a plurality of base stations 6, are regarded as one region is formed.
FIGS. 2A and 2B respectively illustrate cells formed in various shapes in the conventional mobile phone system, and FIGS. 3A and 3B respectively illustrate a cell of which radius is reduced or distorted.
Referring to FIGS. 2A, 2B, 3A, and 3B, for a design convenience of a communication network, the shape of the cell may be considered to be a polygonal shape such as a hexagon 2a and an octagon 2b. In actuality, since the cell has a circle 2c, an overlapped region 2d with an adjacent cell exists. A mobile phone that reaches the overlapped region 2d takes a procedure for changing a base station for providing a better communication environment and a base station (or a cell) for setting a call, such as a hand-off. However, for the reasons of topography, the number of subscribers in a cell and building etc., it is difficult for the cell to keep a circular shape. For example, if a district in which the base station 6 is installed is a farm district where a rice field or a low hill exists, the cell has a similar shape to an idealistic circle. In the farm district, an average of the number of mobile phones that keep a call with one base station 6 is smaller than the number of mobile phones in a dense district such as a city, the radius of the cell increases. On the other hands, if the district in which the base station 6 is installed is a city district in which many high buildings exist or a mountain district, it is difficult for the cell to keep the circular shape. Furthermore, since, in the city district, there are many mobile phones, that is, subscribers, in one cell, the radius of the cell is set to be considerably smaller than compared to the farm district. In the city district, an electric wave sent from the base station 6 is reflected and absorbed by buildings etc., therefore it is difficult to obtain an area of the cell. Since a plurality of mobile phones exists in one building, the number of mobile phones which the base station 6 accommodates may be exceeded. In this case, even if the radius of the cell is set to be 1 km, due to the above-described conditions, it can be reduced to be less than several tens of meters or several meters.
If the mobile phone system provides the cell-based local discount service, due to factors such as area and time etc., even a subscriber who is at the same distance from the predetermined base station 6 may be a subscriber to whom the local discount service is provided and a subscriber to whom the local discount service is not provided. In other words, the local discount service cannot be provided to a subscriber who has subscribed the local discount service, in a corresponding area. For this reason, unlike the object of service provision, a negative effect, such as a service improvement demand or secessions of local discount service subscribers, is generated by a subscriber to whom the local discount service is not provided.
FIG. 4 is a schematic view of a structure of a conventional DU phone service system. Referring to FIG. 4, the DU phone service is a service in which a service area is set and a mobile phone in the set area is connected to a wired phone network 10 using an access point of a service area (not the base station 6). For example, in a conventional wired phone system, an access point 12 which connects a phone 14 to a wired phone network 10 and interworks between a mobile phone 8 and the wired phone network 10 is installed. The access point 12 and the mobile phone 8 perform communication using local area wireless communication technology such as Bluetooth, and a zone 16 which is a service provision area of several or several tens of meters is set using Bluetooth. If a subscriber having the mobile phone 8 enters into the area set by the access point 12, the access point 12 and the mobile phone 8 try to make communication so that it is recognized that the mobile phone 8 is located in a call area via the access point 12. As such, if the subscriber sets the mobile phone 8 in a call mode, the mobile phone 8 tries to make a call not via the mobile phone system but via the access point 12. As a result, the access point 12 tries an interworking between the mobile phone 8 and the wired phone network 10. If the interworking between the mobile phone 8 and the wired phone network 10 is carried out, the mobile phone 8 is used like a portable set of a home wired phone 14. Furthermore, since the subscriber does not use the mobile phone system, the subscriber can make a call at lower wired phone fees than mobile phone fees. In the DU phone service, the service provision area 16 can be more accurately set than local discount in the above-described mobile phone system. Thus, since there is a small variation in the DU phone service, a better local discount service can be provided.
However, in the DU phone service, a subscriber occupies a wired phone line during a call like in the wired phone 14. In the above-described mobile phone service, the radius of the cell 2 is varied regularly and a negative effect thereby exists. However, although a plurality of subscribers exist in the service provision area, each call is reopened for service so that the subscriber can make a call. On the other hands, in the DU phone service, when only one line is installed, if one subscriber occupies a line, another subscriber should use a mobile phone service even in a discount area. To overcome the drawback, an increase in the number of lines of the access point 12 may be considered. However, in this case, a new problem that enormous costs for installing lines should be paid occurs.
Meanwhile, a case where providing a specific service such as discounting fees is provided in a specific area set by mobile communication service providers has been increased. In this case, a method of providing a service by installing a device for setting a service zone so as to set a specific area and setting a radius of a predetermined distance from the device for setting a service zone as the specific area has been used. However, in this case, a global positioning system (GPS) should be used to check the location of the device for setting a service zone. However, at the present, a module using a location information system is expensive, which causes an increase in costs of a mobile communication unit.